Investigation of microbial profile, levels of endotoxin and lipoteichoic acid in teeth with symptomatic irreversible pulpitis: a clinical study.

AIM: To investigate the microbial profile, and levels of endotoxin (LPS) and lipoteichoic acid (LTA), in infected dentine (ID) and root canals (RC) at different phases of root canal treatment in teeth with symptomatic irreversible pulpitis. METHODOLOGY: Ten volunteers were included, and samples were collected from infected dentine (ID) and the root canal lumen (RC) using sterile excavators and paper points, respectively. RC samples were taken before (S1) and after (S2) chemo-mechanical canal preparation (CMP), and after intracanal medication (ICM; S3). Checkerboard DNA-DNA hybridization was used for microbial analysis. The levels of LPS and LTA were evaluated using the limulus amebocyte lysate assay and ELISA, respectively. Shapiro-Wilk's test was used to verify data normality. Friedman's test was used to evaluate statistical differences using checkerboard DNA-DNA hybridization in the ID and RC at the different phases of the RC treatment. Post hoc Dunn's multiple comparison test was used to verify significant differences recorded at the different time-points. The levels of LPS and LTA were analysed statistically by using repeated measures anova and Tukey's post hoc test to evaluate differences in both sites. The significance level was set at 5% (P < 0.05). RESULTS: A total of 40 DNA probes were used for microbial investigation of ID and RC samples using checkerboard DNA-DNA hybridization. The levels and complexity of bacteria were similar in the ID and initial RC samples. The levels of LPS and LTA in ID were significantly higher than the initial RC samples (S1; P < 0.05). Canal preparation was effective in significantly decreasing the levels of bacteria, LPS and LTA (P < 0.05). ICM did not provide additional reduction in the levels of bacteria and LPS (P > 0.05). However, a significant reduction in the levels of LTA was observed after ICM (P < 0.05). CONCLUSION: The microbial profile of infected dentine and root canals of teeth with irreversible pulpitis was complex, harbouring different species including Gram-positive and Gram-negative, cocci and bacilli, and facultative and strict anaerobes. Root canal preparation was effective in reducing the levels of bacteria, LPS and LTA from the root canals of teeth with pulpitis.

Efficacy of reciprocating and ultrasonic activation of 6% sodium hypochlorite in the reduction of microbial content and virulence factors in teeth with primary endodontic infection.

AIM: To evaluate in a clinical trial the efficacy of reciprocating and ultrasonic activation of 6% sodium hypochlorite (NaOCl) in the microbial composition and reduction in microbial load as well as in levels of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) in teeth with primary endodontic infections. METHODOLOGY: Samples were collected from 24 root canals with pulp necrosis and periapical lesions, before and after chemo-mechanical canal preparation. The teeth were randomly divided according to the activation protocol as follows: control group without activation (WA, n = 8), reciprocating activation group using Easy Clean tip (EC, n = 8) and ultrasonic activation group using Irrisonic insert (US, n = 8). Microbiological specimens were processed using a culture technique and microbiota composition was analysed using the checkerboard technique. The levels of LPS and LTA were quantified using limulus amebocyte lysate (LAL) and enzyme-linked immunosorbent assay (ELISA), respectively. The Fisher's exact test, Kruskal-Wallis, Dunn's and Wilcoxon's test with a significance level of P < 0.05 were used for statistical analysis. RESULTS: All initial specimens had growth of viable bacteria in fastidious anaerobe agar (FAA), with an average of 105  CFU mL-1 , whereas only one case had such growth after chemo-mechanical canal preparation. LPS and LTA were recovered in 100% of the cases. Chemo-mechanical canal preparation significantly decreased the levels of LPS and LTA (P < 0.05), but no significant differences were found between the groups (P > 0.05). Through the checkerboard technique, bacteria were found in 100% of the initial specimens with concentrations between <105 and 106 . The most frequently identified microorganisms were Prevotella nigrescens and Enterococcus hirae. After chemo-mechanical canal preparation, many species were not detected in any of the three groups tested. A significant reduction occurred in Group US, followed by Groups EC and WA. CONCLUSIONS: Activation of 6% NaOCl reduced the levels of LPS and LTA with no differences between the groups. However, ultrasonic activation was associated with a greater reduction in microbial load within root canals.

Gender Inequalities in the Dental Workforce: Global Perspectives.

The aim of this review is to investigate the growth of diversity and inclusion in global academic dental research with a focus on gender equality. A diverse range of research methodologies were used to conduct this review, including an extensive review of the literature, engagement of key informants in dental academic leadership positions around the world, and review of current data from a variety of national and international organizations. Results provide evidence of gender inequalities that currently persist in dental academics and research. Although the gender gap among graduating dental students in North America and the two most populous countries in Europe (the United Kingdom and France) has been narrowed, women make up 30% to 40% of registered dentists in countries throughout Europe, Oceania, Asia, and Africa. In academic dentistry around the globe, greater gender inequality was found to correlate with higher ranking academic and leadership positions in the United States, United Kingdom, several countries in European Union, Japan, and Saudi Arabia. Further disparities are noted in the dental research sector, where women make up 33% of dental researchers in the European Union, 35% in North America, 55% in Brazil, and 25% in Japan. Family and societal pressures, limited access to research funding, and lack of mentoring and leadership training opportunities are reported as also contributing to gender inequalities. To continue advancing gender equality in dental academia and research, efforts should be geared toward the collection and public dissemination of data on gender-specific distributions. Such evidence-driven information will guide the selection of future strategies and best practices for promoting gender equity in the dental workforce, which provides a major pipeline of researchers and scholars for the dental profession.

The combined and individual impact of diabetes and smoking on key subgingival periodontal pathogens in patients with chronic periodontitis.

BACKGROUND AND OBJECTIVE: Comprehension of the similarities and differences in the composition of the subgingival microbiota of patients with diabetes mellitus (DM), smokers or smokers with DM is an important step in developing therapies specific for these groups at risk for periodontitis. Therefore, the aim of this study was to compare the combined and individual effects of DM and smoking on the levels and prevalence of key subgingival periodontal pathogens in patients with chronic periodontitis. MATERIAL AND METHODS: One hundred patients with generalized chronic periodontitis were allocated into one of the following groups: DM (n = 25, non-smokers with type 2 DM); S (n = 25, non-diabetic smokers); SDM (n = 25, smokers with type 2 DM); and control (n = 25, non-diabetic non-smokers). Two subgingival biofilm samples from healthy sites (probing depth and clinical attachment level ≤3 mm and no bleeding) and 2 from diseased sites (probing depth and clinical attachment level ≥5 mm and bleeding on probing) were analyzed by quantitative polymerase chain reaction for Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Eubacterium nodatum, Parvimonas micra, Fusobacterium nucleatum ssp. and Prevotella intermedia. RESULTS: There were no differences among groups in the mean counts of the bacterial species studied, considering all sampled sites (healthy plus diseased sites). There were also no differences among groups regarding the prevalence of any bacteria species in healthy and diseased sites (P > .05). The mean P. micra count was significantly higher in the healthy sites of both smoking groups, than in those of the control group (P < .05). CONCLUSION: The subgingival levels and prevalence of the bacterial species studied are not significantly different in subjects with chronic periodontitis presenting DM, smokers or smokers with DM. In addition, DM and smoking, jointly and individually, do not considerably affect the subgingival levels of target periodontal pathogens in patients with chronic periodontitis.

Effects of different periodontal treatments in changing the prevalence and levels of Archaea present in the subgingival biofilm of subjects with periodontitis: A secondary analysis from a randomized controlled clinical trial.

OBJECTIVE: The aim of this randomized double-blind and placebo-controlled study was to assess if periodontal treatment with or without systemic antibiotic would change the mean level of Archaea. METHODS: Fifty-nine (59) subjects were randomly assigned to receive scaling and root planing (SRP) alone or combined with metronidazole (MTZ; 400 mg/TID) or either with MTZ and amoxicillin (AMX; 500 mg/TID) for 14 days. Clinical and microbiological examinations were performed at baseline and at 6 months post-SRP. Six subgingival plaque samples per subject were analysed for the presence and levels of Archaea using quantitative polymerase chain reaction. RESULTS: Scaling and root planing alone or combined with MTZ or MTZ + AMX significantly reduced the prevalence of subjects colonized by Archaea at 6 months post-therapy, without significant differences among groups (P > .05). Both therapies led to a statistically significant decrease in the mean percentage of sites colonized by Archaea (P < .05). The MTZ and MTZ + AMX group had a significantly lower mean number of sites colonized by Archaea and lower levels of these micro-organisms at sites with probing depth ≥5 mm at 6 months compared with SRP group (P < .05). CONCLUSION: Periodontal treatments including adjunctive MTZ or MTZ + AMX are more effective than mechanical treatment alone in reducing the levels and prevalence of sites colonized by Archaea in subjects with chronic periodontitis.

Could cytokine levels in the peri-implant crevicular fluid be used to distinguish between healthy implants and implants with peri-implantitis? A systematic review.

BACKGROUND AND OBJECTIVE: Despite investigative efforts to identify the levels of different types of cytokines in the peri-implant crevicular fluid (PICF), the efficacy of these biomarkers in assisting the diagnosis of peri-implantitis is still undetermined. This systematic review aimed to answer the following question: "Could cytokine levels in the PICF be used to distinguish between healthy implants and implants with peri-implantitis?" MATERIAL AND METHODS: This review was conducted and reported in accordance with the PRISMA statement. The MEDLINE and EMBASE databases were searched from 1990 up to and including March 2015, using MeSH terms and other keywords. Additional publications were searched using a hand search of reference lists of relevant studies. Titles and abstracts were screened and papers that fulfilled eligibility criteria were assessed. RESULTS: Out of 1212 titles, 18 studies reporting the levels of nine different cytokines were included. Proinflammatory cytokines [interleukin (IL)-1ß, IL-6, IL-12, IL-17 and tumor necrosis factor-α) were the cytokines studied most commonly, followed by anti-inflammatory cytokines (IL-4 and IL-10), osteoclastogenesis-related cytokines (RANKL) and chemokines (IL-8). Nine studies reported statistically significantly higher levels of proinflammatory cytokines in the PICF of implants with peri-implantitis than in the PICF of healthy implants. Most studies did not find any significant differences in the PICF levels of anti-inflammatory cytokines and RANKL between healthy implants and implants with peri-implantitis. IL-8 was the only chemokine studied and its levels did not differ significantly between healthy and diseased implants. The studies differed greatly in the manner in which they reported the results (e.g. concentrations or total amounts) and in the exclusion of confounders, such as smoking. CONCLUSION: The results of this systematic review indicate moderate evidence in the literature to support that implants with peri-implantitis present higher levels of proinflammatory cytokines in the PICF than do healthy implants. Evidence regarding the PICF levels of anti-inflammatory cytokines, osteoclastogenesis-related cytokines and chemokines as possible predictors of peri-implantitis is too limited.

Impact of smoking on experimental gingivitis. A clinical, microbiological and immunological prospective study.

OBJECTIVE: The present study assessed the effect of smoking on clinical, microbiological and immunological parameters in an experimental gingivitis model. MATERIAL AND METHODS: Twenty-four healthy dental students were divided into two groups: smokers (n = 10); and nonsmokers (n = 14). Stents were used to prevent biofilm removal during brushing. Visible plaque index (VPI) and gingival bleeding index (GBI) were determined 5- on day -7 (running phase), baseline, 21 d (experimental gingivitis) and 28 d (resolution phase). Supragingival biofilm and gingival crevicular fluid were collected and assayed by checkerboard DNA-DNA hybridization and a multiplex analysis, respectively. Intragroup comparison was performed by Friedman and Dunn's multiple comparison tests, whereas the Mann-Whitney U-test was applied for intergroup analyses. RESULTS: Cessation of oral hygiene resulted in a significant increase in VPI, GBI and gingival crevicular fluid volume in both groups, which returned to baseline levels 7 d after oral hygiene was resumed. Smokers presented lower GBI than did nonsmokers (p < 0.05) at day 21. Smokers had higher total bacterial counts and higher proportions of red- and orange complex bacteria, as well as lower proportions of Actinomyces spp., and of purple- and yellow-complex bacteria (p < 0.05). Furthermore, the levels of key immune-regulatory cytokines, including interleukin (IL)-8, IL-17 and interferon-γ, were higher in smokers than in nonsmokers (p < 0.05). CONCLUSION: Smokers and nonsmokers developed gingival inflammation after supragingival biofilm accumulation, but smokers had less bleeding, higher proportions of periodontal pathogens and distinct host-response patterns during the course of experimental gingivitis.

Subgingival bacterial community profiles in HIV-infected Brazilian adults with chronic periodontitis.

BACKGROUND AND OBJECTIVE: To compare the subgingival microbial diversity between non-HIV-infected and HIV-infected individuals with chronic periodontitis using denaturing gradient gel electrophoresis (DGGE). MATERIAL AND METHODS: Thirty-two patients were selected: 11 were HIV-infected and 21 were non-HIV-infected, and all had chronic periodontitis. Periodontal measurements included probing depth, clinical attachment level, visible supragingival biofilm and bleeding on probing. Subgingival biofilm samples were collected from periodontal sites (50% with probing depth ≤ 4 mm and 50% with probing depth ≥ 5 mm) and whole-genomic-amplified DNA was obtained. The DNA samples were subjected to amplification of a 16S rRNA gene fragment using universal bacterial primers, followed by DGGE analysis of the amplified gene sequences. RESULTS: The non-HIV-infected group presented higher mean full-mouth visible supragingival biofilm (p = 0.004), bleeding on probing (p = 0.006), probing depth (p < 0.001) and clinical attachment level (p = 0.001) in comparison with the HIV-infected group. DGGE analysis revealed 81 distinct bands from all 33 individuals. Banding profiles revealed a higher diversity of the bacterial communities in the subgingival biofilm of HIV-infected patients with chronic periodontitis. Moreover, cluster and principal component analyses demonstrated that the bacterial community profiles differed between these two conditions. High interindividual and intra-individual variability in banding profiles were observed for both groups. CONCLUSION: HIV-infected patients with chronic periodontitis present greater subgingival microbial diversity. In addition, the bacterial communities associated with HIV-infected and non-HIV-infected individuals are different in structure.

Do subjects with aggressive and chronic periodontitis exhibit a different cytokine/chemokine profile in the gingival crevicular fluid? A systematic review.

BACKGROUND AND OBJECTIVE: Microbiological and immunological hypotheses have been raised to explain the differences in the clinical manifestations of aggressive periodontitis and chronic periodontitis. However, studies comparing the cytokine/chemokine profiles in gingival crevicular fluid between these two clinical conditions have so far not been compiled. This systematic review aimed to answer the following question: "Do subjects with aggressive periodontitis and chronic periodontitis have a different profile of cytokines/chemokines in the gingival crevicular fluid?" MATERIAL AND METHODS: An electronic database search of MEDLINE/PubMed and Embase was performed from 1990 up to and including August 2013, using MeSH terms and other keywords. Titles and abstracts were screened and the papers that satisfied eligibility criteria were assessed. RESULTS: Of 1954 titles, 17 studies reporting the levels of 21 different cytokines/chemokines were included. Most studies did not find any significant differences in the gingival crevicular fluid levels of cytokines/chemokines between aggressive periodontitis and chronic periodontitis. Some studies demonstrated that the levels of specific proinflammatory and anti-inflammatory cytokines/chemokines were higher (n = 5) and lower (n = 3), respectively, in aggressive periodontitis than in chronic periodontitis. The studies differed in the manner in which they reported the results (e.g. concentrations or total amounts). It was not clear in some studies whether the sample sites from both groups were matched for disease severity. Some studies did not take into account confounders, such as smoking. CONCLUSION: The current weight of evidence is not sufficient to prove that there are distinct gingival crevicular fluid cytokine/chemokine profiles for patients with aggressive periodontitis and chronic periodontitis.

Absence of interleukin 22 affects the oral microbiota and the progression of induced periapical lesions in murine teeth.

AIM: To evaluate the absence of IL-22 on the progression of periapical lesions in wild-type (WT) and IL-22 knockout (IL-22 KO) mice. METHODOLOGY: The evaluation of the oral microbial profile of mice was performed by Checkerboard DNA-DNA hybridization from saliva samples. Periapical lesions were induced in manbibular first molars by pulpal exposure and evaluated after 7, 21 and 42 days (n = 15). Haematoxylin-eosin-stained sections were analysed under conventional and fluorescence microscopy to evaluate the tissue features and size of periapical lesions and tartrate-resistant acid phosphatase histoenzymology (TRAP), Brown & Brenn staining and immunohistochemistry. The scores of the number of bacterial cells present in the oral cavity were analysed by the Mann-Whitney test, and the results and comparisons for periapical lesion size and number of osteoclasts were subjected to one-way anova and Bonferroni's post-test (α = 0.05). RESULTS: Significant differences were observed for bacterial load between the groups of animals for 6 bacterial species (P < 0.05), with five species found in higher levels in the WT group, and one in the IL-22 KO group. WT mice had significantly larger periapical lesions (P < 0.05) between 7 and 42 days and between 21 and 42 days, with an increase in the mean size and number of osteoclasts. IL-22 KO mice had an increase in periapical lesion size and number of osteoclasts between 7 and 21 days (P < 0.05). No differences were found between bacteria localization in the root canal system between the experimental groups. Small variations related to the location of immunostaining were found between the groups. CONCLUSION: This study revealed differences in the composition of oral microbiota between mice that may be taken into account in the susceptibility to infections and development of periapical lesions. The absence of IL-22 in mice resulted in smaller periapical lesions with fewer osteoclasts at the final experimental period, suggesting the participation of IL-22 in the host immune and inflammatory response to a periradicular infection.

Accuracy of dental calcification stages for the identification of craniofacial pubertal growth spurt: proposal of referral parameters.

PURPOSE: This study primarily aimed to assess the accuracy of radiographic dental calcification parameters for the identification of specific craniofacial growth stages. METHODS: Permanent mandibular canines, premolars, and second molars of 288 patients, from 6 to 15 years old, were analysed on randomly selected panoramic radiographs, and categorised according to two calcification methods. Reproducibility analyses and data derived from panoramic records were correlated with the gold-standard method, as evaluated from lateral cephalometric teleradiographs. Accuracy tests were finally calculated, considering several cutoff points. RESULTS: Dental calcification methods showed "strong" to "almost perfect" intra- and inter-examiner reproducibility. Significant, although weak correlations were observed for all parameters. Canine and first premolar calcification stage 8 and second premolar and second molar stage 7 showed higher sensitivity rates for identifying the pubertal growth spurt period, as well as the stage F for these teeth. Canine and first premolar stages 10 and H obtained higher specificity rates for identifying the absence of post-pubertal period. CONCLUSIONS: The dental calcification parameters showed adequate reproducibility, in addition to significant correlations with cervical vertebrae stages. Radiographic dental calcification parameters used for the mandibular first premolar obtained high accuracy rates and were recommended for identifying specific craniofacial growth periods.

Levels of Selenomonas species in generalized aggressive periodontitis.

BACKGROUND AND OBJECTIVE: To compare the levels of Selenomonas sputigena and uncultivated/unrecognized Selenomonas species in subgingival biofilms from periodontally healthy subjects and from subjects with generalized aggressive periodontitis. MATERIAL AND METHODS: Fifteen periodontally healthy subjects and 15 subjects with generalized aggressive periodontitis were recruited and their clinical periodontal parameters were evaluated. Nine subgingival plaque samples were collected from each subject and all were individually analyzed for the levels of 10 bacterial taxa, including cultured and uncultivated/unrecognized microorganisms, using the RNA-oligonucleotide quantification technique. Between-group differences in the levels of the test taxa were determined using the Mann-Whitney U-test. RESULTS: Subjects with generalized aggressive periodontitis showed significantly higher mean counts of Porphyromonas gingivalis, S. sputigena and the Mitsuokella sp. Human Oral Taxon (HOT) 131 (previously described as Selenomonas sp. oral clone CS002), while higher mean counts of Actinomyces gerencseriae and Streptococcus sanguinis were found in periodontally healthy subjects (p < 0.01). Selenomonas sp. HOT 146 was only detected in the generalized aggressive periodontitis group. In the generalized aggressive periodontitis group, the levels of P. gingivalis and S. sputigena were higher in deep sites (probing depth ≥ 5 mm) than in shallow sites (probing depth ≤ 3 mm) (p < 0.01). Furthermore, in subjects with generalized aggressive periodontitis, sites with probing depth of ≤ 3 mm harbored higher levels of these two species than sites with the same probing depth in periodontally healthy subjects. There were positive correlations between probing depth and the levels of P. gingivalis (r = 0.77; p < 0.01), S. sputigena (r = 0.60; p < 0.01) and Selenomonas dianae (previously described as Selenomonas sp. oral clone EW076) (r = 0.42, p < 0.05). CONCLUSION: S. sputigena and Mitsuokella sp. HOT 131 may be associated with the pathogenesis of generalized aggressive periodontitis, and their role in the onset and progression of this infection should be investigated further.

Partial- and full-mouth scaling and root planing in type 2 diabetic subjects: a 12-mo follow-up of clinical parameters and levels of cytokines and osteoclastogenesis-related factors.

BACKGROUND AND OBJECTIVE: The aim of this study was to evaluate the effects of full-mouth scaling and root planing (FMSRP) and partial-mouth scaling and root planing (PMSRP), up to 12 mo after treatment, on clinical parameters, and levels of cytokines and osteoclastogenesis-related factors in type 2 diabetic subjects with chronic periodontitis. MATERIAL AND METHODS: Thirty-four subjects received FMSRP (n = 17) or PMSRP (n = 17) within 24 h or in multiple sessions, respectively. Clinical parameters and local levels of tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin (IL)-17, IL-23, IL-4, receptor activator of NF-ß ligand and osteoprotegerin were assessed at baseline, and 3, 6 and 12 mo after therapies. RESULTS: Clinical parameters improved after both therapies (p < 0.05), and no between-group differences were observed at any time-point (p > 0.05). Overall, there were no considerable differences in the local levels of the biomarkers studied between groups (p > 0.05). The IL-23 concentration and total amount of IFN-γ increased in the FMSRP group and decreased in the PMSRP group from baseline to 3 mo and from baseline to 6 mo, respectively (p < 0.05). CONCLUSION: Both PMSRP and FMSRP promoted benefits in clinical parameters and showed a similar modulation of cytokines and osteoclastogenesis-related factors at 12 mo in type 2 diabetic subjects.

Prevalence and microbiological diversity of Archaea in peri-implantitis subjects by 16S ribosomal RNA clonal analysis.

BACKGROUND AND OBJECTIVE: This study evaluated the prevalence and the molecular diversity of Archaea in the subgingival biofilm samples of subjects with peri-implantitis. MATERIAL AND METHODS: Fifty subjects were assigned into two groups: Control (n = 25), consisting of subjects with healthy implants; and Test (n = 25), consisting of subjects with peri-implantitis sites, as well as a healthy implant. In the Test group, subgingival biofilm samples were taken from the deepest sites of the diseased implant. In both groups, subgingival biofilm was collected from one site with a healthy implant and from one site with a periodontally healthy tooth. DNA was extracted and the 16S ribosomal RNA gene was amplified with universal primer pairs for Archaea. Amplified genes were cloned and sequenced, and the phylotypes were identified by comparison with known 16S ribosomal RNA sequences. RESULTS: In the Control group, Archaea were detected in two and three sites of the implant and the tooth, respectively. In the Test group, Archaea were detected in 12, 4 and 2 sites of diseased implants, healthy implants and teeth, respectively. Diseased implants presented a significantly higher prevalence of Archaea in comparison with healthy implants and natural teeth, irrespective of group. Over 90% of the clone libraries were formed by Methanobrevibacter oralis, which was detected in both groups. Methanobacterium congelense/curvum was detected in four subjects from the Test group and in two subjects from the Control group. CONCLUSION: Although M. oralis was the main species of Archaea associated with both healthy and diseased implant sites, the data indicated an increased prevalence of Archaea in peri-implantitis sites, and their role in pathogenesis should be further investigated.

Immune response to cytolethal distending toxin of Aggregatibacter actinomycetemcomitans in periodontitis patients.

BACKGROUND AND OBJECTIVE: Cytolethal distending toxin (CDT) is a genotoxin produced by Aggregatibacter actinomycetemcomitans. In spite of its association with pathogenesis, little is known about the humoral immune response against the CDT. This study aimed to test whether subgingival colonization and humoral response to A. actinomycetemcomitans would lead to a response against CDT. MATERIAL AND METHODS: Sera from periodontally healthy, localized and generalized aggressive periodontitis and chronic periodontitis subjects (n = 80) were assessed for immunoglobulin G titers to A. actinomycetemcomitans serotypes a/b/c and to each CDT subunit (CdtA, CdtB and CdtC) by ELISA. A. actinomycetemcomitans subgingival levels and neutralization of CDT activity were also analyzed. RESULTS: Sera from 75.0% localized and 81.8% generalized aggressive periodontitis patients reacted to A. actinomycetemcomitans. A response to serotype b was detected in localized (66.7%) and generalized aggressive periodontitis (54.5%). Reactivity to A. actinomycetemcomitans correlated with subgingival colonization (R = 0.75, p < 0.05). There was no correlation between A. actinomycetemcomitans colonization or response to serotypes and the immunoglobulin G response to CDT subunits. Titers of immunoglobulin G to CdtA and CdtB did not differ among groups; however, sera of all generalized aggressive periodontitis patients reacted to CdtC. Neutralization of CDT was not correlated with levels of antibodies to CDT subunits. CONCLUSION: Response to CdtA and CdtB did not correlate with the periodontal status of the subject in the context of an A. actinomycetemcomitans infection. However, a response to CdtC was found in sera of generalized but not of localized aggressive periodontitis subjects. Differences in response to CdtC between generalized and localized aggressive periodontitis subjects indicate that CDT could be expressed differently by the infecting strains. Alternatively, the antibody response to CdtC could require the colonization of multiple sites.

Comparative analysis of endodontic pathogens using checkerboard hybridization in relation to culture.

BACKGROUND/AIM: The purpose of this study was to detect bacterial species and to quantify the total number of bacteria from samples of infected root canals before (S1) and after chemo-mechanical preparation using 2% chlorhexidine (CHX) gel as auxiliary chemical substance (S2) and after 7 days of intracanal dressing (S3) to compare microbial changes. METHOD: Twenty-four teeth were selected for this study. Chemo-mechanical preparation was performed using 2% CHX gel, then three different intracanal medicaments [M1: Ca(OH)(2) paste; M2: 2% CHX gel; and M3: Ca(OH)(2) paste plus 2% CHX gel] were used for 7 days. Checkerboard DNA-DNA hybridization was performed to detect 40 bacterial species. Aerobic and anaerobic culture techniques were used to determine the bacterial community by counting the colony-forming units (CFU). RESULTS: The species most frequently identified by checkerboard in S1 were: Fusobacterium nucleatum ssp. polymorphum, Treponema socranskii ssp. socranskii, Parvimonas micra and Enterococcus faecalis. In S2 and S3 a total of eight different species were identified; and only one of them was gram-positive (E. faecalis). Microorganisms were not identified after use of M2 for 7 days. The quantification obtained on agar plates ranged from 4 x 10(5) to 2.6 x 10(6) CFU/ml in S1, mean CFU was reduced by 99.96% in S2, and there was no statistical difference between the CFU in S2 and S3. CONCLUSION: The antibacterial effect of the mechanical preparation supplemented by the use of an antibacterial auxiliary substance greatly reduced the microorganisms in the main root canal.

The relationship between periodontal disease and preterm low birthweight: clinical and microbiological results.

BACKGROUND AND OBJECTIVE: Findings on the effect of periodontal disease on preterm low birthweight are inconclusive. The objective of this study was to compare periodontal clinical measures and the levels and proportions of 39 bacterial species in subgingival biofilm samples in puerperal women with preterm low birthweight and nonpreterm low birthweight. MATERIAL AND METHODS: A case-control study with 116 postpartum women over 30 years of age was conducted. Four case groups of subjects with preterm and/or low birthweight [preterm (n = 40), low birthweight (n = 35), preterm and/or low birthweight (n = 50) and preterm and low birthweight (n = 25)] were compared with normal nonpreterm low-birthweight controls (n = 66). Periodontal clinical parameters of dental plaque, calculus, bleeding on probing, periodontal pocket depth and clinical attachment level were recorded. Covariates included socio-demographic and anthropometric characteristics, smoking, alcohol consumption, obstetric history, prenatal care and diseases during pregnancy. Two subgingival biofilm samples per women were analyzed for 39 bacterial species using a checkerboard DNA-DNA hybridization technique. RESULTS: The mean periodontal pocket depth was significantly higher in nonpreterm low-birthweight controls than in subjects in the preterm low birthweight, preterm and/or low birthweight, and preterm and low-birthweight groups. Clinical attachment level measures were not different between all pairs of cases and control groups. Groups did not differ with respect to the mean proportions of different microbial complexes. The mean counts of Treponema socranskii were lower in all case groups compared with the control group. CONCLUSION: Maternal periodontal microbiota and clinical characteristics of periodontal disease were not associated with having preterm low-birthweight babies.

Microbiological evaluation of primary endodontic infections in teeth with and without sinus tract.

AIM: To examine the microbiological status of primary endodontic infections in teeth with and without a sinus tract. METHODOLOGY: Samples were collected by means of a size 15 H-type file and two sterile paper points from 30 cases of primary endodontic infections with (n = 15) or without (n = 15) a sinus tract. The presence of 40 bacterial species was determined by the checkerboard DNA-DNA hybridization method. RESULTS: The species found at the highest levels and prevalence were Fusobacterium nucleatum sp. vincentii, Porphyromonas gingivalis, Veillonella parvula, Enterococcus faecalis, Campylobacter gracilis and Neisseria mucosa. Total bacterial counts were similar between teeth with (44 x 10(5)) and without (50 x 10(5)) a sinus tract (t-test: P > 0.05). E. faecalis, Streptococcus anginosus, Capnocytophaga sputigena and Capnocytophaga gingivalis had significantly higher counts in the absence of sinus tract (Mann-Whitney test, P < 0.05). Higher levels of P. gingivalis and Fusobacterium nucleatum sp. nucleatum were observed in cases with a sinus tract. Leptotrichia buccalis (OR = 1.83; CI 95%) and Porphyromonas endodontalis (OR = 2.15; CI 95%) were associated with an increased chance of subjects having a sinus tract. CONCLUSIONS: Primary endodontic infections were associated with a large variety of bacterial species. Specific differences between the composition of the microbiota of primary root canal infections were observed in cases with or without a sinus tract.

Levels of Candidate Periodontal Pathogens in Subgingival Biofilm.

In recent years, several new periodontal taxa have been associated with the etiology of periodontitis. A recent systematic review provides further support for the pathogenic role of 17 species/phylotypes. Thus, the aim of this study was to assess the prevalence and levels of these species in subjects with generalized chronic periodontitis (GChP; n = 30), generalized aggressive periodontitis (GAgP; n = 30), and periodontal health (PH; n = 30). All subjects underwent clinical and microbiological assessment. Nine subgingival plaque samples were collected from each subject and analyzed for their content of 20 bacterial species/phylotypes through the RNA-oligonucleotide quantification technique. Subjects from the GChP and GAgP groups presented the highest mean values for all clinical parameters in comparison with the PH group (P < 0.05). Subjects with GChP and GAgP showed significantly higher mean levels of Bacteroidetes sp. human oral taxon (HOT) 274, Fretibacterium sp. HOT 360, and TM7 sp. HOT 356 phylotypes, as well as higher mean levels of Filifactor alocis, Fretibacterium fastidiosum, Porphyromonas gingivalis, Tannerella forsythia, and Selenomonas sputigena species than PH subjects (P < 0.05). GAgP subjects presented higher mean levels of TM7 sp. HOT 356 and F. alocis than GChP subjects (P < 0.05). A significantly higher mean prevalence of Bacteroidales sp. HOT 274, Desulfobulbus sp. HOT 041, Fretibacterium sp. HOT 360, and Fretibacterium sp. HOT 362 was found in subjects with GChP and GAgP than in PH subjects. Mean levels of P. gingivalis (r = 0.68), T. forsythia (r = 0.62), F. alocis (r = 0.51, P = 0.001), and Fretibacterium sp. HOT 360 (r = 0.41) were correlated with pocket depth (P < 0.001). In conclusion, Bacteroidales sp. HOT 274, Desulfobulbus sp. HOT 041, Fretibacterium sp. HOT 360, Fretibacterium sp. HOT 362, and TM7 sp. HOT 356 phylotypes, in addition to F. alocis, F. fastidiosum, and S. sputigena, seem to be associated with periodontitis, and their role in periodontal pathogenesis should be further investigated.